Louis, who attends Nower Hill High School in George V Avenue, Pinner, said: “My friend William has lost his hair again and has a very big challenge ahead.

“I kept on thinking, what I could to help?

“I know seeing each other a lot is important but I just wanted to do more, so I have decided to shave my hair off just like his and raise as much money as I can for Great Ormond Street Hospital, who are doing their best to find the best treatment for him.

“It is a horrible thing to happen to anyone, especially your best friend.”

Louis went to Andy’s Barbers Lounge in Eastcote on Tuesday with brother Callum, 16, father Steve and William - a pupil at Haydon School in Wiltshire Lane, Eastcote - to lose his curly locks.

It marked the launch of a fundraising drive to earn £2,500 for Great Ormond Street Hospital Children’s Charity and to show his support for his best friend.

The Low family live in Pinner and William's mother Helen Forbes-Low said: “We are deeply touched by Louis's gesture, it's such a wonderful thing to do.

“Support from our friends has carried us through these difficult times.

“We would like to thank everyone for their support and for donating to justgiving.com to support Great Ormond Street Hospital.”